1. Technical Field of the Invention
This invention relates to a urethral plug assembly having an adhesive coating thereon, enabling it to maintain stability in urethra. "Mechanical" or "Mechanically" is defined as that which operates by the motion of solid elements. "Fluid" or "Fluidly" is defined as that which operates without the use of solid element, but rather operates with a liquid or gaseous material.
2. Description of the Prior Art
Urinary stress incontinence is defined as the involuntary loss of urine when the pressure within the urethra exceeds the maximum urethral pressure required for maintaining closure. While the problem of urinary incontinence occurs in men and women, it is an affliction especially common in women of child bearing age and beyond.
There are in existence many methods used to address the problem of incontinence. Bladder neck suspension surgery, wherein the neck of the bladder is reduced by suspending the bladder, is perhaps the most desirable way to treat incontinence, especially in younger patients. However, there are numerous risks associated with such surgery, notwithstanding the expense. For some patients, surgery is not recommended for medical or other reasons, and for those with mild incontinence surgery is not an appropriate solution.
As an alternative to surgical correction, devices have been developed to address the problem of urinary incontinence. Many of these devices require surgery for implantation, and of these surgically implanted devices, there are two distinct types: non-manipulable devices and manipulable devices. One such non-manipulable device, described in U.S. Pat. No. 4,019,499, is a capsule filled with a variable amount of fluid. The capsule is surgically implanted between supporting tissue and the urethra to exert an occluding force thereon. A similar, non-manipulable capsule implant is described in U.S. Pat. No. 3,789,828. However, this device has ties extending therefrom to aid in fiber ingrowth, thus providing mechanical stability to the capsule. One problem associated with this device is the risk of fluid leakage. In addition to problems with leakage, severe tissue damage may result from the unnatural method in which such devices regulate incontinence.
Other surgically implanted devices exist which are manipulable. These devices provide the wearer with the ability to selectively control the operation of the device via manually operable elements implanted in the tissue surrounding the urethra. U.S. Pat. No. 4,428,365, and U.S. Pat. No. 4,846,784 each disclose an indwelling device having an inflatable chamber with an attached tubing and an inflation bulb. The wearer may manually adjust the pressure exhibited by the inflatable member on the urethra, simply by squeezing the tissue encasing the bulb. These devices, however, often produce thickening and scarring of surrounding tissue, making their usefulness questionable. Additional adverse effects associated with surgically implanted indwelling devices, whether non-manipulable or manipulable in nature, are encrustation, irritation and infection.
There are also known in the art certain indwelling devices that do not require surgical implantation. These devices are inserted by a physician through the urethral orifice and allow the wearer to void either past or through the device. An example of such a device is disclosed in U.S. Pat. No. 4,850,963 in which a physician inserts a bolus of ferromagnetic material through the urethra and into the bladder. The bolus rests at the juncture of the bladder and urethra and is moved for bladder evacuation, by the relative positioning of a magnet across the body of the wearer. However, the bolus may become lodged in an area beyond the reaches of the magnetic force exhibited by the magnet, making the device inoperative. Another example of this type of indwelling device is the prestressed capsule disclosed in U.S. Pat. No. 4,457,299. The capsule is inserted by a physician within the lower interior of the urethra and is set at a prestressed pressure slightly above involuntary pressure. When the urine pressure exceeds the preset pressure of the capsule, the capsule deforms allowing urine to flow around the device. This device, however, has no feature to prevent migration of the device into the bladder. In U.S. Pat. No. 4,553,533 there is shown a prosthetic urethral sphincter valve which is placed in the urethra and anchored in the bladder. The patient increases his bladder pressure by means of a valsalva maneuver, and holds this pressure while the valve activates. Urine may then pass through the valve with the valve later returning to its closed position. This device is very complicated, expensive, difficult to manufacture and uncomfortable. Another physician-inserted device is disclosed in U.S. Pat. No. 3,797,478. This device has an expandable collar which is inflated after insertion, by an injection of fluid therein. When it is desired to remove the device, the inflated collar is ruptured or serrated, thus expelling the fluid into the wearer's body. Notwithstanding the cumbrous use of this device, there is a risk of infection associated with the release of injection fluid upon removal. Similarly, U.S. Pat. No. 3,841,304 discloses a plug which is inserted by a physician into the urethra and subsequently inflated to block the flow of urine. This device may be left in the body for extended periods. After insertion, the device merely requires repositioning in the urethra to permit bladder evacuation. Such a device leaves the wearer susceptible to infection, as bacteria may be introduced into the urethra during repositioning, or during indwelling time. Also, serious complications can occur upon removal, when a separate wire must be inserted therein. These devices being indwelling, are often cumbersome to the wearer and often cause numerous complications such as encrustation, irritation and infection.
Also known in the art are devices capable of being inserted by the wearer into the urethra. Such devices are removed for voiding, and then reintroduced into the urethra upon completion of bladder evacuation. An example of such a device is the solid-type urethral plug, described by Neilsen, Kurt K. et al., in "The Urethral Plug: A New Treatment Modality for Genuine Urinary Stress Incontinence in Women" J. Urology, vol. 44, p. 1100 (1990). This device consists of one or two solid spheres located along a soft shaft, and a thin, soft plate located at the end of the shaft. One sphere is located upstream of the maximum urethral closing pressure point, corresponding to the location of the sphincter. In the two sphere embodiment, the second sphere is located with its midpoint at the bladder neck, and is used to assist in reducing urinary flow and pressure transmission to the urethra so that the sphincter can operate. When the patient wants to evacuate the bladder, the plug is removed, evacuation occurs, and a fresh plug is inserted. One problem associated with this device is that the patient must have three urethral closure pressure profiles performed as well as other examinations, before the device is made for the wearer. Additional problems associated with this device include placement difficulties, lack of sealing capabilities associated therewith, inadequate retention thereby allowing expelling and inadequate anchoring by the plate at the meatus. In addition, such problems is the discomfort associated with insertion and removal, due to the size profile and rigidity of the spheres, which maintain a constant diameter during insertion, and removal. Another "remove-to-void" device is disclosed in U.S. Pat. No. 5,090,424, which comprises a conformable urethral plug. The body of the plug forms a cavity which is in fluid communication with another cavity via a check-valve. Thus, fluid may be pumped into the cavity within the urethra to provide a custom fit. This device, like many others relying on liquids or gels for expansion, relies heavily on a fluid-tight valve in order to maintain retention. Should valve failure occur, evacuation would immediately follow. There is also a chance of fluid leakage into the body of the wearer should rupture of the plug occur.
There are also known in the art certain external devices that do not require insertion into the urethra. Urine absorbing pads have been developed to collect and absorb urine as it flows out of the body. Such pads have difficulty retaining a stationary position and often lack effectiveness in preventing leakage. An example of an external device in which such problems have been addressed is the urine absorbing pad disclosed in U.S. Pat. No. 5,074,855. This device employs adhesive to secure a pad to the vestibule such that urine is absorbed as it is expelled from the body. However, there are many disadvantages associated with such a device. Urine buildup in the urethra creating an uncomfortable sensation for the wearer is-one such disadvantage. Additionally, due to the structure and function of such a device, there is nothing to increase urethral resistance to urine flow. Moreover, as such a pad is designed only to be worn externally, it is subject to migration in the course of one's daily movement and activities, even with the use of adhesive given the friction associated with undergarments contacting the pad. Migration as such, increases the likelihood of accidents and leakage. Although this pad attempts to seal and absorb urine at the meatus, the meatus is not physiologically blocked thus the wearer is susceptible to discomfort and leakage. This device, given its structure and composition, would not be effective internally due to the differing physiological conditions present in the urethra, bladder neck or bladder, where internal conditions such as high temperature and moisture levels exist.
As evidenced by the above discussion, problems associated with the stability of urinary incontinence devices have not been adequately addressed in the prior art. Prior art devices have focused solely on sizing a device such that the urethra is occluded, without addressing the need for enhancing the retention and sealing capabilities of such devices.
In view of the above problems associated with the prior art, an easily manipulable, "remove-to-void", indwelling urethral plug assembly having enhanced retention and sealing capabilities would be desirable to those afflicted with urinary incontinence.